(Spectroscopic FITS headers situation as of 2015-06-27)

1.  RBT (PST2) raw spectra (before any reduction):

1.1  Made before 2014-04-05

DATE - UT file creation after exposure and CCD readout (NTP synced PC clock)
FRAME - UT file creation after exposure and CCD readout (NTP synced PC clock)
JD - UT file creation after exposure and CCD readout - calculated from DATE
JDCENTER - UT weighted exposition center - experimental

1.2  Made after 2014-04-05

DATE - UT file creation after exposure and CCD readout (NTP synced PC clock)
DATE-BEG - UT exposure start (NTP synced PC clock)
JD - UT exposure start - calculated from DATE-BEG
JDCENTER - UT weighted exposition center - experimental

2.  RBT (PST2) reduced spectra:

2.1  Reduced before 2015-06-27

Only spectra made before 2014-04-05 should have correct time:
DATE - last modification time (by IRAF)
DATE-OBS - exposure start UT
JD - mid-exposure UT
HJD - mid-exposure UT [this is usable only in RA and DEC are correct]
JDCENTER - UT weighted exposition center - experimental
Spectra made after 2014-04-05 have SHIFTED time after reduction:
DATE - last modification time (by IRAF)
DATE-BEG - exposure start UT
DATE-OBS - exposure start UT + (full exposure time) + (CCD readout time)
JD - mid-exposure UT + (full exposure time) + (CCD readout time)
HJD - mid-exposure UT + (full exposure time) + (CCD readout time) [this is usable only in RA and DEC are correct]
JDCENTER - UT weighted exposition center - experimental

2.2  Reduced after 2015-06-27

All spectra should have correct time:
DATE - last modification time (by IRAF)
DATE-BEG - exposure start UT
DATE-OBS - exposure start UT
JD - mid-exposure UT
HJD - mid-exposure UT [this is usable only in RA and DEC are correct]
JDCENTER - UT weighted exposition center - experimental

3.  PST (PST1) raw spectra (before any reduction):

3.1  Made before 2014-09-26

DATE - UT exposure start (NTP synced PC clock)

3.2  Made after 2014-09-26

DATE - UT file creation after exposure and CCD readout (NTP synced PC clock)

3.3  Made after 2015-07-02 12:00 UT

DATE - UT file creation after exposure and CCD readout (NTP synced PC clock)
DATE-BEG - UT exposure start (NTP synced PC clock)

4.  PST (PST1) reduced spectra:

4.1  Reduced before 2015-06-27

Only spectra made before 2014-09-26 should have correct time:
DATE - last modification time (by IRAF)
DATE-OBS - exposure start UT
JD - mid-exposure UT
HJD - mid-exposure UT
Spectra made after 2014-09-26 have SHIFTED time after reduction:
DATE - last modification time (by IRAF)
DATE-OBS - exposure start UT + (full exposure time) + (CCD readout time)
JD - mid-exposure UT + (full exposure time) + (CCD readout time)
HJD - mid-exposure UT + (full exposure time) + (CCD readout time) [this is usable only in RA and DEC are correct]

4.2  Reduced after 2015-06-27

All spectra should have correct time:
DATE - last modification time (by IRAF)
DATE-OBS - exposure start UT
JD - mid-exposure UT
HJD - mid-exposure UT
Page last modified on October 23, 2016, at 01:23 AM